It is well established that ceramides have a vital role in the production and maintenance of the water permeability barrier of the skin. Ceramides, or substances closely related to them, have been widely disclosed as components of skin care compositions. Of particular interest in this respect is the disclosure by Kao Corporation in EP 0227994 of synthetic analogues of ceramides which, to a significant extent, have similar properties to natural ceramides but which are relatively cheaper to produce.
However, the degree of skin benefit attributable to such natural ceramides or analogues thereof is limited to the extent that they do not fully mimic the natural ceramides of the skin. Unilever NV in EP 0 097 059 disclosed the vital role played by .omega.-linoleoyl ceramides in the water barrier of the skin and described the synthesis and application for skin care of such .omega.-substituted ceramides. Application of this latter invention is however limited due to the high cost of synthesis and limited availability of the naturally occurring compounds.